1. Field of the Invention
The present invention relates to illumination in general, and more particularly to vehicular headlights.
2. Description of the Related Art
There are already known various constructions of headlights for motor vehicles, among them those for motor vehicles that are designed for travel on paved roads, more often than not in close proximity to oncoming traffic moving in the opposite direction. In this scenario, it is important that the headlight issue a so-called low beam of light which is aimed in such a manner as to sufficiently illuminate the pavement ahead of the vehicle but not to dazzle or blind the driver of the oncoming vehicle. Of course, the headlight may also be, and almost without exception is, equipped to issue a so-called high beam as well which illuminates not only the roadway to a much greater distance in front of the vehicle but also a region at the side of the road and above the road where various signs depicting information that may be of value to the vehicle driver in navigating or maneuvering the vehicle may be located. Unfortunately, experience has shown that, with the prevalence of motor vehicles nowadays, the vehicle driver may have to cover substantial distances before being able to switch the high beams on without endangering himself or herself and the occupants of oncoming vehicles by dazzling or temporarily blinding their drivers. The low beam, on the other hand, due to its very nature, does a poor and inadequate job in illuminating such signs, especially the overhead ones.
This problem has already been recognized and dealt with before, for instance in the German patent publication DE 44 13 833 A1. This headlight serves for the issuance of at least the aforementioned low beam and includes a light source and a reflector. In the path of propagation of the light beam that is formed by the reflection of the light emitted by the light source by the reflecting surface of the reflector, there is arranged a light-transmissive plate which includes optical profiles by which the light rays of the light beam passing through the plate are deflected from their original courses. The reflector reflects the light of the light source that reaches it reflection surface in the form of a light beam that exhibits an upper light/dark boundary. This headlight is further provided with a reflection element by which the light emitted by the light source is reflected as an additional light beam propagating upwardly of the aforementioned upper light/dark boundary of the low light beam. The reflection element is provided on a light ray shutter which is coated with a reflective layer for this purpose. The intention is for the light reflected from the reflection element to illuminate a spatial region situated above the light/dark boundary without interference with the vision of the drivers of the oncoming vehicles approaching in the opposite direction of travel, so that especially overhead signs that are located high above the roadway are sufficiently illuminated. The light ray shutter that constitutes the reflection element in this patent document must be produced and mounted as a separate part and its position with respect to the other components of the headlight must be precisely adjusted so as to assure the illumination of, and only of, the desired spatial region by the additional light beam. This is a very laborious procedure which entails high manufacturing and assembly expenditures.
Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide a headlight equipped to illuminate overhead signs when operated as a low light beam source, which headlight does not possess the drawbacks of the known headlights of this type.
Still another object of the present invention is to devise a headlight of the type here under consideration which does not require the performance of extensive and expensive adjustment operations.
It is yet another object of the present invention to design the above headlight in such a manner as to be able to dispense with previously required additional manufacturing and assembly steps.
A concomitant object of the present invention is so to construct the headlight of the above type as to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet reliable in operation.
In keeping with the above objects and others which will become apparent hereafter, one feature of the present invention resides in a vehicular headlight which includes at least one light source that emits light when in use; a reflector having a main reflection surface so positioned relative to the light source as to reflect any light reaching the same from the light source in the form of at least a low light beam delimited at least by an upper light/dark boundary at its upper region as considered in the position in which the headlight is to be used; and a light-transmitting plate extending across the path of the light beam at a distance from the light source and at least substantially devoid of any optically active profiles. The headlight of the present invention further includes a reflection element integral with the reflector and having an additional reflection surface deviating in configuration from that of the basic reflection surface and reflecting any light reaching the same from the light source in the form of an additional light beam to an additional region situated upwardly of the upper light/dark boundary. A particular advantage of the present invention as described so far is that, due to the fact that the reflection element is constituted by an integral part of the reflector, there is no need for conducting any additional and separate manufacturing and/or assembly operation for the reflection element.
A particularly advantageous construction of the headlight of the present invention is obtained when the reflection element is arranged at a border region of the reflector, especially at a lower portion of such border region as considered in the position of use. This solution has the advantage that the configuration of the reflector is impaired to the least possible extent when the reflection element is located at such a region and/or portion. In this context, it is particularly advantageous when a fold is present at least at an upper portion of the transition between the additional reflection surface of the reflection element and the basic reflection surface of the reflector. This assures that no undesired reflections will occur at this transition region.
According to another advantageous aspect of the present invention, the additional reflection surface of the reflection element is at least substantially planar. However, it is also proposed by the present invention for the additional reflection surface of the reflection element to be concavely curved.
In accordance with another facet of the present invention, the width of the additional reflection surface of the reflection element in the horizontal direction is greater than the height of the additional reflection surface of the reflection element in the horizontal direction, both as considered in the position of use of the headlight. Last but not least, it is to be mentioned that an important feature of the present invention is that the additional reflection surface of the reflection element is so configured that the light emitted by the light source and reaching the same is reflected therefrom as a light beam that is horizontally dispersed as considered in the position of use.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.